Magnetic storage and switching structure



July 5, 1960 H. c. KUNTZLEMAN' 2,944,249

MAGNETIC STORAGE AND SWITCHING STRUCTURE INVENTOR HARRY C. KUNTZLEMAN ATTORNEY in Fig. l with the lines of magnetic flux indicated for a value stored V t V i Fig. 3 is the same portion of Fig. 1 shown in Fig. 2

t r United States Patent 0 Ice with the lines of magnetic flux indicated for sensing the value stored in the magnetic core; I 2,944,249 Referring to Fig. 1 there is shown a closed loop mag- I netic core 4 having substantial magnetic retentivity and "MAGNETIC SWITCHING 5 a rectangularhysteresis loop. Materials of this type 4 are well known'and are commonly used as magnetic core -Harry C. Kuntzleman, Newark Valley, N.Y., assignor to storage elements. Core-4 has a figure eight type winding glnternational Business Machines Corporation, New 5 threaded therethrough so that one half of the core 'ksfl -a a corporation of New o may be saturated in one direction while the other half I Filed Dents, 195$"S6LN6783913 of the core is saturated in the opposite direction. This establishes two pnmary magnet1c circuits in the core 4. 8 Claims. (Cl. 340-474) Although a figure eight winding is shown, it may be desirable to provide two distinct windings,- one for each V I half of the core with suitable driving means to produce This invention relates to magnetic core storage and the relatively large flux needed to saturate the two halves switching devices and more particulary to such devices of the core in opposite directions. The arrows indicate in which one of a plurality of values may be stored or the directions of magnetization produced by the winding switched. 5 when energized by a current pulse passed therethrough. In prior devices, magnetic cores have been used to One of the two primary magnetic circuits extends around store one of a plurality of values by driving the core the outer half of the closed loop core and encompasses to a particular level of magnetic retentivity and deter- I the areas designated III and IV, while the other primary mining the value stored by resetting the core to a spe'cimagnetic circuit extends around the inner half of the fied level of retentivity and discriminating the amplitude closed loop and encompasses the area designated II. It ofthe signal thus produced to determine the value stored. should be noted that the cross-sectional area of leg I The preferred embodiment of the present invention conof the core should be equal to or greater than the sum templates the use of a single magnetic core encompassing of the cross-sectional areas of legs II, III and IV as india plurality of magnetic circuits which magnetic circuits cated on the core in Fig. 1. In-order to store a value are each capable of storing asignal by virtue of the rein core 4, it isnecessary that the winding 5 be pulsed to tentiv-ity of the individual magnetic circuits. In this set the two primary circuits of the core into opposite manner, one of a plurality of values may be stored withstates of magnetic retentivity as indicatedabove. If it out resort to amplitude discrimination. is desirable'to disable the core such that it may not be Accordingly, an object of this invention is to provide caused to store'a value, the winding 6 may be impulsed an improved magnetic storage and switching device. simultaneously with'the application of the pulse to wind- Another object is to provide an improved magnetic ing-S to thus prevent the two primary magnetic circuits core storage device capable of storing one of a plurality assuming opposite states of magnetic retentivity. Second- -of values. 'ary windings 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 are According to a preferred embodiment of the present provided to respectively store the values arbitrarily chosen invention, a single magnetic core structure contains two as one through ten. -The secondary windings '7 through primary magnetic'circuits magnetized in opposite di- 16 cooperate withthe core4 to provide ten-secondary rections. A plurality of secondary magnetic circuits are 40 magnetic'circuits in'core 4 disposed between the two provided between the two primary circuits and when primary magnetic circuits mentioned above. The secondselectively energized reverse the magnetization in a 'por- .ary magnetic circuits of course overlap the primary tion of each of the two primary circuits. The several magnetic circuits to someextent. As arbitrarily chosen, secondary circuits may each be assigned an arbitary the secondarymagnetic circuit around aperture17 stores value. The energization of a particular secondary circuit a decimal one when energized, the secondary magnetic thus stores the value assigned thereto. An auxiliary magv circuit around aperture 18 stores a decimal two when netic circuit is provided in the core for each secondary energized, etc. Any of the windings 7 through 16 may circuit for sensing the state of magnetization of the be'selectively chosen to store any of the ten decimal secondary circuit associated therewith. The operation values. By selecting one of the windings 7 through 16 of the auxiliary. circuits does not change the state of the and applying a current pulse therethrough, the core area secondary circuits, and thus the sensing of information about the selected winding is magnetized in a particular in the core is nondestructive, and consequently the way. For storing a one, for example, thewinding 7 is sensing of the information in the core may be repeated as energized and reverses the flux established by the figure often as desired without regeneration. eight winding in a portion of the two primary magnetic Another object of this invention is to provide an imcircuits. This is indicated in Fig. 2 by the dotted lines proved magnetic core storage device capable of storing around aperture 17. It may be seen from Fig. 2 that one of a plurality of values and capable of being sensed the core retains remanent magnetization around aperture without destroying the value stored. 17 and that this magnetization is the reverse of that estab- O'ther'objects of the invention will be pointed out in lished in the two primary magnetic circuits in that por- "the following description and claims and illustrated in tion of the primary circuits common 'to the selected secthe accompanying drawings, which disclose, byway of ondary magnetic circuit. Although the core str'u'ct u're examples, the principle of the invention and the best as shown is adapted for storing values in the: decimal mode, which has been contemplated, of applying that 7 system of notation, it will be apparent'that the structure principle. may be adapted vfor storing the various values in' any a; In the drawings: system of notation byproviding thereq'uired number of 'f sFig. 1 isa schematic diagram ofa core storage and apertures andwindings and byassigning the secondary switching structure-constructed in accordance with the magnetic circuits appropriately designated values; lf it :present invention. is desired to store a one, for example, in the core of-Fig. Fig.'2-is' a portion of the core storage device shown 1, the winding7 is supplied with apulse which establishes lines of flux around apert ure 17 as shown ,in Fig.2. Since the core has substantial'retentivity, these lines of flux'will remain after the pulse on line 7 dies away.'

An auxiliary magnetic circuit is provided for each of the secondary magnetic circuits to sense the state of the secondary magnetic circuit and thus determine the value stored. A plurality of windings, 21 through 30, are threaded through core 4, respectively adjacent the secondary magnetic circuits having windings 7 through 16. The secondary magnetic circuit around aperture 17, for example, has associated with it the auxiliary magnetic circuit around adjacent aperture 32.' The s econdary magnetic circuit around aperture 18 is associated with the auxiliary magnetic circuit around aperture 33, etc. With a value stored in thecore as indicated in Fig. 2, the winding 21 of the auxiliary magnetic circuit around aperture 32 is energized or pulsed to sense the state of the secondary circuit. The auxiliary magnetic circuit around aperture 32 overlaps the secondary magnetic circuit surrounding aperture 17 associated with winding 7 and is utilized to sense the state of the secondary magnetic circuit surrounding aperture 17.

In order to sense the core or read out the value stored therein, a current pulse is supplied through winding 21, for example. This current pulse induces a flux in core 4 in the direction indicated by the solid line arrow of Fig. 3. Current through winding 21 in cooperation with the secondary magnetic circuit around aperture 17 sets up flux paths around aperture 32. as shown by the dotted lines of Fig. 3. In response to the reversal of flux around aperture 32, an output winding 34 has a signal induced therein to indicate the fact that a value was stored by the secondary magnetic circuit surrounding aperture 17. If the line 7 has not been pulsed to store a value in the core about aperture 17, the lines of flux about apertures 17 and 32 will remain as shown by solid arrows in Fig. 1. If in this condition a pulse is applied through winding 21, the portion of the core about aperture 3'2 oflers a low impedance to winding 21 and transfers little energy to winding 34. This results from the fact that a portion of the magnetic path about aperture 32 is in a state of retentivity of the same direction as the flux induced by a pulse through winding 21 regardless of the direction of the current pulse through winding 21. The portion of the magnetic path about aperture 32 having retained magnetic flux of the same direction as the induced flux acts in the same manner as an air gap might act and prevents a reversal of flux about aperture 32 to thus prevent any substantial output signal on winding 34 when winding 21 is pulsed. Output windings 34 through 43 are associated with the auxiliary magnetic circuits and may supply output signals to any desired utilization device.

A source 44 provides a sample or read out pulse to winding 29. Each of the windings 21 through 30 is provided with a like source, or if desired, all these wind-.

ing may be driven by a common source with appropriate switching. The source 44 provides a positive going waveform followed by a negative going waveform as shown in Fig. l. The positive going portion of the waveform senses the state of the associated secondary magnetic circuit, and the negative going portion returns the auxiliary circuit to the initial state. This operation leaves any secondary circuit in the same state that it had before sensing. Thus, the sensing of data in the secondary circuits is nondestructive and may be repeated asoften as required Without regeneration. With the arrangement shown, a single core structure is capable of storing any of the values in the decimalsystem of notation.

\While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention.

It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. A storage device for storing one of a plurality of values comprising a magnetic core of a material having substantial retentivity and containing a pair of primary magnetic circuits, means for magnetizing said primary circuits in opposite directions, a plurality of secondary magnetic circuits disposed in said core betweensaid primary circuits, means for energizing one of said secondary circuits to alter the direction of magnetization ina portion of each of said primary circuits and stor'e -the value assigned to the secondary circuit energized, and an auxiliary magnetic circuit associated with each of said secondary circuits for sensing the state of the associated secondary circuit.

2. A magnetic core structure for storing one of a plurality of values comprising a closed loop magnetic core of material having substantial rententivity, first andv second primary magnetic circuits in said core, means for energizing said first circuit to magnetize a first portion of said core in a first direction, means for energizing said second circuit to magnetize a second portion of said core in a second opposite direction, a plurality of secondary magnetic circuits disposed between said primary circuits, means for energizing a selected one of said plurality of secondary circuits to alter the direction of magnetization in a portion of each of said primary circuits, and an auxiliary magnetic circuit assoicated with each of said secondary circuits for sensing the state of the associated secondary circuit. 7

3. A magnetic core structure for storing one of a plurality of values comprising a closed loop magnetic core of material having substantial rententivity, first and second primary magnetic circuits extending around the closed loop of said magnetic core, means for energizing said first circuit to magnetize a firs-t loopof said core in a first direction, means for energizing said second circuit to magnetize a second loop of said core in a second opposite direction, a plurality of secondary magnetic cir-- cuits disposed between said first and said second loops, means for energizing a. selected one of said plurality of secondary circuits to alter the direction of magnetization in a portion of said first and second loops of said core to store the value assigned to the selected secondary. circuit, and an auxiliary magnetic circuit for each of said secondary circuits disposed in one of said loops of said core for sensing the state of the associated secondary circuits.

4. A magnetic core structure for storing one of a plurality of values comprising a closed loop magnetic core of material having substantial retentivity, first, and second primary magnetic circuits extending around different portions of the closed loop of said magnetic core, means for energizing said first and second primary circuits in opposite directions to magnetize said diiferent portions of the closed loop of said core in opposite directions, a plurality of secondary magnetic circuits disposed between said first and second primary magnetic circuits, means for selectively energizing said plurality of secondary circuits to reverse the direction of magnetization in a portion of said first and said second mag netic circuits adjacent the selected secondary circuit and store the value assigned to the selected secondary circuit, and an auxiliary magnetic circuit for each'of said secondary circuits disposed in said core adjacent the associated secondary circuit for sensing the states ofisaid secondary circuits to determine the value stored therein.

5. Apparatus according to claim 4 wherein said means for energizing said primary circuits comprises a winding I 'a first portion of the core in one direction and a second portion of the core in a second opposite direction. U

6 Apparatus according to claim 4 whereinsaid rneans for selectively energizing said secondary circuits comprise windings threaded through said magnetic core between said different portions of the closed loop of said core.

7. Apparatus according to claim 4 wherein said auxiliary magnetic circuits include a sense winding threaded through said core adjacent each of said secondary magnetic circuits and an output winding threaded through said core adjacent each of said secondary magnetic circuits.

8. Apparatus according to claim 7 wherein said means for selectively energizing said secondary circuits comprise windings threaded .through said magnetic core between said different portions of the closed loop of said core.

References Cited in the file of this patent IBM Technical Disclosure Bulletin, vol. No. 2, August 1958, Flux Shifting Device, by Bauer and Butler (1 page). 

